5i'
SECTION 3
GENERAL PROVISIONS CONCERNING USERS
Recommendation E.120
INSTRUCTIONS FOR USERS OF
THE INTERNATIONAL TELEPHONE SERVICE
Preamble
This Recommendation outlines the principles and guidelines for
Administrations in the preparation of user instructions.
The growth of the worldwide telephone network emphasizes the
urgency to improve customer performance when using telecommunica-
tions services. The absence of clear and up-to-date information and
instructions for users of the worldwide telephone service can only
result in a low degree of customer satisfaction and unnecessarily
high costs to Administrations. Consequently, Administrations are
urged to promote, through the use of this Recommendation, progress
towards the adoption of the guidelines which follow.
1 General principles
1.1 Up-to-date comprehensive instructions should be made
readily available to users of the public telephone service , by
Administrations.
1.2 The objective of such instructions is to allow customers
to complete calls themselves to the maximum extent possible and
reduce errors in the use of the international network, thus:
- assisting the user and providing greater satis-
faction on his part,
- effecting significant cost savings by Adminis-
trations through more efficient use of the network.
_________________________
Other Recommendations which should be considered in
this respect are: E.115, E.121, E.122, E.123, E.126,
E.127, E.128, E.160, E.161.
1.3 On this basis, the full availability of current instruc-
tions should be considered as equally important as the overall
planning, provisioning, operating and maintaining processes, the
costs of which are a normal and inherent part of the supplying of
good telecommunications service.
1.4 Established instructions provided by Administrations
should be evaluated on a regular and continuing basis with a view
to their improvement. Observations of service quality, studies of
customer calling difficulties, questionnaires, customer comments,
laboratory experiments, and any other means which may be available
or practicable should be considered the normal tools for furnishing
good instructions.
1.5.1 The introduction of new services shall include clear and
easy to use instructions for use by the customer. These instruc-
tions constitute a normal part of the introduction of these ser-
vices.
1.5.2 Every effort should be made to test the effectiveness of
instructions before issue and then to promote and promulgate on an
international basis those proven to be most effective in practice,
with due regard to the needs of different countries.
1.5.3 Design of instructions should play a key role in the
development of proposed new services, from the customer point of
view, rather than being considered belatedly in operational and
hardware decision making and manufacture.
1.5.4 Optimal instructional practices as proved in service
might be made available to all interested Administrations in order
to improve customer performance and effect significant cost sav-
ings.
2 Instructions
2.1 The most common means of providing a range of instructions
and information to customers for the effective use of the telephone
service is through the medium of printed public telephone direc-
tories issued on a general basis by Administrations.
2.2 In addition, these printed instructions should normally be
placed in public places for use by customers, such as public tele-
phone booths and post offices.
2.3 Further instructions for specific purposes may be issued
to users, for example:
- dialling instruction booklets,
- dialling code booklets,
- operating procedure booklets (for supplementary
services),
- personal telephone directories,
- other telephone guide books (multilingual), pam-
phlets or cards of a specialized nature.
2.4 Access to spoken instructions can be provided through the
provision of operators or recorded announcement machines dedicated
to this activity; one aim should be to reduce to the greatest
extent customer references to the operator assistance service.
2.5 Specialized instruction can with advantage be given
through the medium of inclusion in school curriculums, radio broad-
cast and television transmissions, other printed media and special
public presentations for the purpose of improving customer perfor-
mance.
3 Public telephone directories
3.1 Public telephone directories are published regularly by
Administrations as the most common means of informing customers of
service numbers which are generally available for public use,
instructions on use of the service, and easy to find current custo-
mer telephone number listings. It is recognized that the layout of
directories is governed by considerations which may vary from coun-
try to country; however, it is desirable that such lists of sub-
scribers should be capable of ready consultation by the Administra-
tions and/or subscribers of other countries. To this end, similar-
ity in sequence and presentation of directory information should be
regarded as a desirable international objective to be achieved
within the constraints of language differences.
3.2 Such information can be conveyed by words, pictograms and
internationally standardized symbols, the basic need being to
impart clear information to the caller (see Recommendation E.121).
It would be very useful, in order to encourage the use of the
international telephone service, if directories (especially those
supplied to other Administrations and/or to subscribers of other
countries) were composed in roman characters, particularly those
relating to the names and addresses of subscribers.
3.3 Public telephone directories may cover a single numbering
plan area, or several numbering plan areas on an exchange or geo-
graphical basis or portions thereof based on a community of
interest and are issued free of charge to subscribers in these
areas.
3.4 They may be published as a single volume or as groups of
volumes, keeping in mind the need for brevity and simplicity, regu-
lar editing and up-to-date publication, consistency between
volumes, for maximum readability and ease of use by the customer.
Each volume of the lists of subscribers could usefully contain a
recapitulatory list of the subdivisions mentioned in the volume, or
an equivalent chart.
3.5 Language difference on the part of residents and foreign
visitors is an important factor to be considered in the publica-
tion of public telephone directories. Multilingual information,
when included, should be well presented so that those who have par-
tial knowledge of, or no language of the country are not deterred
from using the service.
3.6 To avoid difficulties in the interpretation of instruc-
tions due to language differences, the harmonization of the General
Information pages in the telephone directory must be continued. In
these pages, instructions are clearly and concisely given by means
of recommended symbols and pictograms and by graphical representa-
tion of the operational procedures of the telephone service (see
Recommendation E.126).
3.7 Moreover, with a view to reducing the difficulties experi-
enced by foreign visitors in consulting the first pages of the
telephone directory, some of these pages should contain a summary
of the essential information in different foreign languages with
references to the full text of the instructions given in the "Gen-
eral Information pages" in the national language (see
Recommendation E.127).
3.8 Public telephone directories should be subdivided into at
least two basic parts easily recognizable, for example by means of
different coloured pages (for example, pink for instructional pages
and white for customer telephone number listings). Page
edge-marking or intercover publicity are other alternatives.
3.8.1 Call guide instructions for users should consist, for
example, of the following, in order of priority:
- index;
- emergency call numbers (police, fire, ambulance,
language service, etc.);
- service department codes and operator assistance
numbers;
- how to dial;
- local dialling instructions with lists of
exchange or geographic place names, codes, maps of area coverage
and applicable charges if any;
- national long-distance dialling instructions,
with lists of place names, long-distance prefixes, area codes, maps
and details of call charges;
- international long-distance dialling instruc-
tions, with international prefixes, country codes, area codes and
details of call charges, etc.;
- how to use the directory;
- general information which the Administration may
feel useful or important to the user;
- examples drawn from Recommendation E.123 to
illustrate the standard national and international notation for
telephone numbers, to facilitate understanding of the composition
of international numbers;
- numbers of the administrative services of
Administrations, their addresses and enquiry points;
- list of codes and telephone numbers of the tele-
phone services which are available, together with recommended sym-
bols to assist foreign visitors.
3.8.2 Customer listings
- Alphabetical lists in black print on white pages
of subscribers (surname, given names or initials and postal
address) either by numbering plan, exchange or geographical area
(or combinations thereof) with an appropriate identification in
heavier type at the beginning of the list and at the top of each
page and/or column.
- Listings belonging to another directory area
including those of other countries should be easily distinguish-
able, and show the appropriate information in order that a call can
be completed.
- Alphabetical lists may be split where desired,
into residence and business listings.
3.8.3 The instructional pages should precede the customer
listings.
3.8.4 Where there is a need for more than one language in a
country, colours or other means of differentiation may be used as
appropriate in the instructional pages.
3.9 The same directory may contain sections other than the
alphabetical list of subscribers, but these sections may equally be
published as a separate volume or volumes, for example:
3.9.1 Classified listings (Yellow pages)
- a classified business trade and professional sec-
tion in alphabetical order, followed by names in alphabetical order
under the respective headings, together with address and telephone
number.
3.9.2 Services promotion (Green pages)
- a section or filler pages to allow the Adminis-
tration to illustrate services it wishes to sell, or makes avail-
able free of charge, and provide instructions for specialized
instruments which may be connected to the network, in addition to
other information (e.g. postal or telegraph information, PBXs,
telex or data services). Photographs, recommended pictograms and
symbols could be used, particularly to help foreign visitors to
take advantage of the services.
3.9.3 Optional classified listings and service promotion sec-
tions should follow the instructional pages and customer listings
so as not to negate the basic nature of the latter, from the users'
point of view.
3.10 It is desirable that the effectiveness of the existing
public telephone directories should be tested periodically in order
to improve customer performance in the use of the network.
3.11 The front cover or the first pages of each book of a
directory, or each section of a directory, should preferably be
used to emphasize important information such as emergency numbers
although these may be also listed elsewhere.
3.12 Other information deemed important by Administrations,
for example national laws or regulations, billing information, etc.
might be placed on the back pages or spare pages due to the binding
process. These pages might also be used for personal notation of
telephone numbers to increase the value of the directory from the
users' point of view.
3.13 Administrations may wish to consider the use of staff
dedicated to the improvement of directory listings, resolution of
particular listing problems and which can ensure a source of addi-
tional revenue (e.g. additional listings).
3.14 Recommendation E.114 outlines the conditions for supply-
ing lists of subscribers (by directories and other means) to other
Administrations.
4 Public telephone booths
4.1 Public telephone booths should preferably be identified
externally with the applicable internationally approved symbols,
particularly at locations frequented by tourists.
4.2 In addition, they should be equipped with public telephone
directories relative to the areas in which they are located and
associated calling instruction booklets as appropriate.
4.3 Public telephone booths should, as necessary, prominently
display notices listing exchanges which can be reached without
dialling the full national number. Lists of dialling codes, partic-
ularly those most frequently used should also be displayed to
reduce enquiries to operators to the minimum.
4.4 Public telephone booths should display relevant pictograms
and symbols to instruct customers on how to place national and
international calls, to obtain assistance from operators, or to
place calls to emergency numbers (fire, police, etc.). (See
Recommendation E.121.)
4.5 Administrations should preferably display instructional
information in more than one language and give careful considera-
tion to the use of several languages for maximum assistance, par-
ticularly in call offices and transport terminals where foreign
visitors can be expected and so help reduce costly operating assis-
tance services.
Harmonization of the human factor aspects of payphones may be
an efficient means not only of ensuring the correct use of pay-
phones in the international telephone service but also of obviating
the need for different instructions to foreign visitors, which may
become virtually superfluous in the future.
4.6 Similarly, instructional information regarding other ser-
vices provided by the Administration may be posted.
5 Instructional information for specific purposes
5.1 Considering the scope, size and normal availability of
public telephone directories, the ease and need of travel by users,
the increasing use and reliability of telecommunications and the
lack of knowledge on the part of foreign visitors, then personal-
ized instructional information should be made available.
5.2 This generally takes the form of personal pocket informa-
tion issued to new customers, either residence or business, heavy
users, or generally available upon request. Such information
includes:
- dialling instruction booklets,
- dialling code booklets,
- operating procedure booklets,
- personal telephone directories,
- other telephone guide books, pamphlets or cards.
5.3 Administrations should consider making appropriate infor-
mation available to foreign visitors and to their customers who
plan to visit other countries or who otherwise have a need. This
might be arranged and exchanged on a bilateral basis for mutual
benefit.
5.4 Careful attention should be directed to publishing
instructions in more than one language to ensure as wide a use as
possible. The use of appropriate pictograms and symbols of the
recommended design would assist the customer in unfamiliar situa-
tions (see Recommendation E.121).
5.5 Dialling instruction booklets are published to facilitate
the placing of national calls and international calls. Ideally,
instructions for both should be in the same booklet and should be
essentially the same as provided in public telephone directories.
Since the characteristics of payphones at present differ from
one country to another, detailed instructions should be provided
for identifying payphones, for making national and international
calls correctly from them and for correctly paying for the calls.
5.6 Dialling code booklets should similarly list the appropri-
ate codes for national and international calls, in separate sec-
tions of the same booklet.
5.7 Operating procedure booklets may be essentially the same
as dialling code booklets but include appropriate control pro-
cedures for special services which the customer may want to use,
preferably of an internationally standardized nature.
5.8 Special cards or specialized leaflets may also be made
available to illustrate, for example:
- dialling codes or instructions for foreign visi-
tors on how to make national and international calls;
- tones which may be encountered in dialling
national or international calls, illustrated by pictograms or
internationally standardized symbols;
- use of particular services that are available or
whose proper use should be encouraged;
- practical or helpful hints to foreign visitors
regarding any aspect of the service;
- guidance to travellers telephoning home from
abroad (see Supplement No. 6 at the end of this fascicle).
5.9 The above-mentioned leaflets and Supplement No. 6 should
so far as possible be combined, provided that this arrangement is
convenient for users (see Recommendation E.128).
5.10 Personal telephone directories can be particularly useful
to users for their notation of particular or frequently called
numbers. Administrations could consider the inclusion of a minimal
amount of key instructional information.
5.11 Administrations are encouraged to establish and maintain
close liaison with other countries' tourist boards to ensure that
current information about its services is available to prospective
visitors in suitably translated form.
6 Instructions by operators or recorded announcements
6.1 Correct dialling instructions can be given to customers as
required in the process of placing a call, by special intercept
operators or recorded announcements dedicated to that type of
instruction.
6.2 This may be given in more than one language, or the custo-
mer directed to an appropriate language operator for assistance.
Inferred is special training on the part of the operators.
6.3 Recorded announcement machines may be employed on a public
basis, where feasible, to which users could be encouraged to call
for instructional information (e.g. demonstration of foreign tones
or announcements, etc.).
6.4 To aid in a clearer understanding of the world's telephone
system, a verbal announcement used within the various networks
should preferably be interleaved with the special information tone
(SIT).
Note - This tone is internationally standardized and designed
to invite a calling subscriber to get in touch with an operator in
his country when he cannot understand a message aurally received.
6.5 It is paramount that if recorded announcements are used,
the words should be chosen with extreme care to avoid customer con-
fusion.
7 Specialized instructions
7.1 Administrations may choose to employ specialized instruc-
tions in a formal manner through other media for example:
- educational programmes in elementary or more
advanced school curriculums,
- educational programmes and aids for teachers,
- radio broadcasts or television transmissions of
instructional information, exclusive of advertising,
- presentation of instructions through newspapers
or magazines,
- film presentations to private groups, or to
larger public groups in cinemas,
- presentations at local, national or international
exhibitions,
- special inserts with customer accounts,
- special leaflets for restricted or wide distribu-
tion,
- special classes on customers', or Administration,
premises (e.g. PBX or Centrex users, etc.),
- change of number postcards and letterhead stick-
ers for individual subscriber use, etc.
For the training of future users, who may become an increas-
ingly important part of worldwide telecommunications customers,
some of the above items may be applicable.
7.2 Some such programmes may be more effective than others and
while efficacy may be difficult to determine, evaluation is an
important aspect towards optimum instruction at least cost.
Recommendation E.121
PICTOGRAMS AND SYMBOLS TO ASSIST USERS OF |
THE TELEPHONE SERVICE
1 General definitions and guidelines
1.1 Definitions
pictograms and symbols convey information in pictorial form.
They are widely used in the telecommunication field to denote
specific types of equipment and services and to instruct people in
the use of such equipment and services.
A pictogram is a simplified pictorial representation. It is
commonly used to guide people and tell the person how to achieve a
certain goal. It consists of more or less realistic elements. Pic-
tograms should be self-explanatory.
A symbol is an abstract pictorial representation; it commonly
stands for something and tells a person what he is faced with. It
is not necessarily realistic and often requires a learning process
in order to be understood.
There is not always a sharp distinction between pictograms and
symbols. Pictorial representations can be placed on a continuum
with on the one end realistic pictograms which can be readily
understood and on the other end abstract symbols which are diffi-
cult to understand without prior learning.
1.2 Pictograms and symbols as an alternative to written
text
Advantages of pictograms and symbols as compared with written
text are:
- independence of language;
- greater efficiency in denoting direction and
other special attributes;
- greater spatial compactness;
- faster visual perception;
- more eye-catching.
Disadvantages of pictograms and symbols as compared with writ-
ten text are:
- less efficiency in conveying detailed informa-
tion;
- greater risk of incorrect interpretation;
- for abstract symbols, the need of some prior
learning in order to be correctly understood.
Pictorial representation of an abstract concept should only be
used instead of written text if the user can be assumed to have
adequate opportunity for learning (for instance through frequent
usage).
To prevent incorrect interpretation, pictograms or symbols may
be accompanied by supplementary text. This is especially advisable
if correct interpretation could be of vital importance to the user.
An additional and important advantage of supplementary text is that
it facilitates the learning of symbols and pictograms.
1.3 Guidelines for design
The idea for a pictorial design for a particular application
should, whenever possible, be based on the user's mental picture of
that application.
Realistic pictograms are more self-explanatory and require
less learning than abstract symbols. Hence, whenever possible, the
designer should aim at realistic representation.
To achieve fast visual recognition, a pictogram or symbol
should be as simple as possible and it should be easily distin-
guishable from other currently used pictograms and symbols.
The design of a consistent set of symbols should be guided by
a few unambiguous rules about the meaning of pictorial elements
within a particular application and the relationship between these
elements (see, for example, S 2.5.3). The set should not be larger
than strictly necessary; a maximum of three different elements is
recommended.
The design of pictograms and symbols should meet the technical
requirements of their application. If they are to be displayed on
the individual keys of a keyboard or on a VDU screen, their design
should allow this without essential modification. In both these
cases they should be easily recognizable from a distance of 50 cm.
1.4 Guidelines for testing
To find the most suitable symbol or pictogram for a particular
application, it is advisable that a number of different designs be
generated and submitted for testing.
The method of testing a pictogram or symbol should depend on
its intended application. If the application offers little or no
opportunity for learning, the test should determine the degree of
correct recognition without prior learning. If the application
allows prior learning, the test should determine how many trials
are needed to arrive at a previously determined criterion of
correct recognition. If a pictogram or symbol is to be used in con-
junction with other pictograms or symbols, it should be tested
within the context of these other symbols of pictograms (see, for
an example, Annex A).
1.5 Standardization
Great advantages accrue when the meaning of symbols and picto-
grams becomes common knowledge. It follows that standardization is
desirable, especially when such standardization can be in confor-
mity with existing standards produced by other standards organiza-
tions.
1.6 Design specifications
The styling, size, colour and position of each recommended
symbol or pictogram is left to the discretion of the Administra-
tion. Each symbol or pictogram should, however, bear a close per-
ceptual similarity to those shown in this Recommendation.
Figure titles for Figures 1/E.121 through 4/E.121 and 7/E.121
give those pictorial elements which are considered essential. Sym-
bols may be contained within a suitable frame or border.
2 Specific recommendations
2.1 Symbol for telephone
A symbol for telephone may be used:
a) in place of the word telephone;
b) as an adjunct to a telephone number ;
c) to indicate a place where telephone calls can be
made;
d) to refer to the telephone service in general.
When such a symbol is used, it should be a representation of a
telephone handset. The symbol given here (Figure 1/E.121) is simi-
lar to the one cited in [1] and those commonly found on road
traffic signs and in railway stations
Figure 1/E.121, p.1
2.2 Symbol for information
A symbol for information can be used in telephone directories
, in lists of relevant telephone numbers shown in telephone booths,
in other places where information via the telephone can be given,
or in printed information for foreign visitors. It may also be used
in association with several telephone (service) numbers. It may be
used to draw attention to:
a) general telephone service information ;
b) information about national or international
telephone numbers;
c) assistance in foreign languages ;
d) information about hotels, theatres, etc.
When such a symbol is used, it should consist of the letter i
(lower case) as shown in Figure 2/E.121. The symbol may be con-
tained within a suitable frame or border. Since this symbol is a
general reference, it should be associated with appropriate words
or other symbols to show the nature of the information provided at
the corresponding telephone number. For example, the symbol "tele-
phone" for general telephone inquiry and the words "English",
"Deutsch", "Francais" for assistance in foreign languages.
Figure 2/E.121, p.
2.3 Symbols for emergency numbers
In some countries a general emergency number is available to
be dialled in all emergency situations. In other countries dif-
ferent telephone numbers are used for each emergency service such
as fire brigade, ambulance or police. Where a symbol is used to
indicate the general emergency number, that symbol should be "SOS"
as shown in Figure 3/E.121. Where no general emergency number
exists, the symbol may be used to draw attention to the list of
emergency numbers.
Figure 3/E.121, p.
The symbols shown in Figure 4/E.121 may be used in cases where
different symbols are required, possibly in combination with
Figure 3/E.121.
Figure 4/E.121, p.4
Administrations may judge it necessary to test these symbols
in the context of other, nationally used, symbols. Annex A provides
a method for such a test.
The three symbols in Figure 4/E.121 were selected by means of
an international experiment performed in eight countries. Alto-
gether, 364 subjects participated in this experiment. The results
of this experiment show a remarkable consistency in the results
from the eight countries.
2.4 Graphical representation of audible tones
2.4.1 A graphical representation of audible tones in instruc-
tions is recognized as a means, in addition to a verbal descrip-
tion, that could aid telephone users to interpret them correctly
during the process of setting up a call. The definition of
principles for a graphical representation which would guarantee the
maximum aid to users has been studied during the Study
Period 1977-1980. Certain experiments designed by Working
Party II/2 have been carried out with the participation of the fol-
lowing countries: Australia, Canada, Denmark, the Netherlands,
Nigeria, Norway, Sweden and the United Kingdom.
2.4.2 An additional study has been done during the Study
Period 1981-1984 in the United Kingdom. This study supported
results of earlier studies.
2.4.3 Audible tones known to exist at the present time in
various national networks can be characterized by the following
factors:
- temporal structure,
- pitch,
- tone quality or timbre (subjectively felt by the
users and related to the spectral complexity),
- loudness.
These four factors should be graphically represented according
to the following principles:
2.4.3.1 Temporal structure
This factor should be represented by appropriate blank inter-
vals along a horizontal time axis.
For example:
Figure, (recup.) p.
2.4.3.2 Pitch variation in a tone
This factor should be represented by the vertical displacement
of a linear element above the time axis.
Figure, (recup.) p.
2.4.3.3 Tone quality
Pure tones (sinusoidal waves) should be represented by linear
elements on a horizontal axis.
Figure, (recup.) p.
If non-pure tones consist of two frequencies, the optimal
representation depends on the frequency difference between the
tones. This frequency difference may be greater than the critical
bandwidth (consonant tone-pairs) or smaller (dissonant
tone-pairs) [2]; for consonant tone-pairs , the optimal representa-
tion is two parallel linear elements; for dissonant tone-pairs , a
wavy line is optimal.
Figure, (recup.) p.
If the frequency difference between the two tones is near the
critical bandwidth, neither of the representations may be satisfac-
tory.
2.4.3.4 Loudness variation in the tone
This factor should be represented by variation in the thick-
ness of a linear element.
Figure, (recup.) p.
2.4.4 Intermittent tones should normally be represented by at
least 2 full cycles.
2.4.5 The same time scale should be used in the representation
of all tones in the same figure.
2.5 Symbols for supplementary services
2.5.1 Symbols may be used to designate telephone subscriber
services. They may appear on subscriber equipment, e.g. on the
tops of push-buttons by which these services are operated. They may
also be used in instructional material name - of being independent
_________________________
At the time these symbols were developed and tested,
the procedures by which subscriber services are operat-
ed were not yet standardized. This may lead to the un-
desirable situation that the same symbol is used for
different procedural implementations of a service. Ef-
forts have therefore to be made to standardize the
operational procedures for supplementary services.
of language. For users familiar with a certain language, the full
name or a mnemonic code may be more easily understood.
2.5.2 Figure 5/E.121 shows symbols for twelve supplementary
services experiments in which the symbols were evaluated (see
Annex B). They are chosen in such a way that they explain the
operation of the services in clear and simple terms. Where applica-
ble, the corresponding names as they appear in Supplement No. 1 are
added in parentheses, together with the relevant paragraph numbers.
2.5.3 The set of symbols recommended here is open to future
expansion, if symbols for more services should be required.
The majority of the standardized symbols are based on the fol-
lowing guiding principles:
- a point represents a subscriber's station;
- a line between points represents a connection
between subscribers;
- a dashed line represents a connection on the
hold;
- an arrow represents a call:
outgoing calls . | | | an arrow away from the
user ^
incoming calls . | | | an arrow toward the user
v
calls passing by . | | | an arrow passing by the
user
Example: Basic diversion ("Incoming call passes
by") MONTAGE
Example: Enquiry call ("First party on hold whilst
calling another party") MONTAGE
- a bar (or "barrier") represents a "stop" for a
call; Example: Incoming calls barred MON-
TAGE
- a repeated action is represented by repeated sym-
bol elements; Example: Repeat last call
MONTAGE
- ringing is represented by stylized sound waves
outgoing from a point; Example: No reply diversion
MONTAGE
The number of symbols combining these elements is limited.
Therefore, for some of the standardized symbols, additional ele-
ments have had to be applied:
- a keystroke is represented by a square;
Example: Short code dialling ("One keystroke
instead of many") MONTAGE
- A disconnection is represented by an interrupted
line. Example: Disconnect MONTAGE
2.5.4 If manufacturers or Administrations consider using sym-
bols which are not yet recommended, they are advised to contact the
CCITT Secretariat, which will in turn contact the Special Rappor-
teur for the relevant Question.
2.5.5 The symbols presented in Figure 5/E.121 may also be
displayed on a CRT as long as they appear closely similar to their
presentation on paper. On a commonly available CRT screen, this can
be achieved by using a minimum of 60 | (mu | 0 or 60 | (mu | 0 pix-
els per symbol.
2.6 Pictographic instructions for payphones
A sequence of pictograms is an effective means of instructing
users of payphones , especially if certain users, e.g. foreign
visitors , are not familiar with the equipment or operating pro-
cedures. Various studies on the design of pictographic instructions
for payphones have led to the following guidelines:
2.6.1 If it is likely that certain users will be unfamiliar
with the equipment (e.g. foreign visitors), realistic drawings
showing the equipment sufficiently to locate the different parts
would be helpful; where it is likely that users will be familiar
with the equipment, or that locating the different elements is not
a problem, less representative pictograms may be acceptable.
2.6.2 Movement (or certain actions) should be indicated by
arrows. These could be provided in a different colour from the rest
of the pictogram, for greater conspicuousness.
2.6.3 Movement, or actions, in a sequence of pictographic
instructions, should be labelled by numbers 1, 2, 3, etc. in the
appropriate order.
Pictograms can be arranged in a horizontal strip (as illus-
trated in Figure 6/E.121) or in a vertical column, or (provided
that the numbering is clear), in a block.
2.6.4 Pictograms should be placed where they will most easily
be seen by the user and, wherever possible, should be fastened to
the body of the equipment. Ideally, new payphones should be
designed with a space on the front specifically to accommodate the
pictograms, and the larger the space allowed, the better.
2.6.5 New pictogram designs should be tested in realistic con-
ditions on a sample of the user population before being implemented
generally.
2.7 Symbol for facsimile
A symbol for facsimile may be used:
a) in place of the word facsimile;
b) to indicate a place where a facsimile service
can be used;
c) to refer to the facsimile service in general;
d) as an adjunct to the facsimile number of a sub-
scriber (see also Recommendation E.123, S 7).
When such a symbol is used, it should consist of the word FAX
in capital letters as indicated in Figure 7/E.121.
Figure 5/E.121, p.11
Figure 6/E.121, p.12
Figure 7/E.121, p.13
2.8 Symbol of access for the physically handicapped
A symbol of access for the physically handicapped may be used
to indicate that a public telecommunication facility such as a
telephone booth is accessible to a handicapped person, particularly
one using a wheelchair.
The symbol to be used for this purpose is the symbol in
Figure 8/E.121. This symbol has been adopted for international
standardization in a resolution of the l978 assembly of Rehabilita-
tion International. For specific regulations regarding the design
and application of this symbol, it is recommended that Administra-
tions contact their national member organization of Rehabilitation
International or the central office of Rehabilitation
International, 25 East Street, New York, 10010, USA.
Figure 7/8.121, p.
2.9 Symbol for special facilities for the deaf and hard of
hearing
A symbol for special facilities for the deaf and hard of hear-
ing may be used to indicate that a telecommunication facility such
as a public telephone has been specially adapted for the deaf
and/or hard of hearing. Such special facilities may consist either
of amplification or of textual presentation.
The symbol to be used for these purposes is the symbol in
Figure 9/E.121. This symbol was adopted by the World Federation of
the Deaf during their meeting in 1980. For specific regulations
regarding the design and applications of this symbol, it is recom-
mended that Administrations contact their national member organiza-
tion of the World Federation of the Deaf or the General Secretariat
of this organization at 120 Via Gregorio VII, 00165 Rome, Italy.
Figure 9/8.121, p.
ANNEX A
(to Recommendation E.121)
Procedure for supplementary context experiment
for further evaluation of auxiliary symbols for
SOS services
A.1 Recommended emergency symbols may further be tested in a
so-called "context" experiment. Such a context experiment could be
carried out by countries who wish to use emergency symbols in con-
junction with other national pictograms and/or symbols. The purpose
of a context experiment would be to estimate whether this joint
presentation of a set of different symbols would lead to confusion
errors, either:
- because an SOS service would be selected when
another service indicated by a national symbol was intended, or
- because another service indicated by a national
symbol was selected when one of the SOS services was intended.
This annex gives a broad outline of the procedure that could
be followed to carry out such an experiment. It involves a simple
paper-and-pencil task in which subjects have to select an appropri-
ate symbol out of a set of others.
A.2 Subjects
At least 40 subjects should be used. They should be more or
less representative of the public at large and they should not be
professionally connected with telecommunications or visual design
activities.
A.3 Selection of symbols
The set of symbols to be investigated should include the three
SOS symbols as well as all other symbols which may be used to indi-
cate other telephone numbers.
A.4 Experimental task
The subject's task is to match each symbol to its particular
service by selecting an appropriate telephone number. For this pur-
pose, he is presented with a set of papers. On each paper, the
whole set of symbols with matching telephone numbers is presented.
The sequence in which the symbols are presented on a page is ran-
domly varied between pages. At the bottom of each page appear two
questions to be answered:
1) If I wanted to contact the POST OFFICE I would
dial
(Fill in the appropriate telephone number.)
2) I am VERY CERTAIN / RATHER CERTAIN / UNCERTAIN
that my answer is correct.
(Circle one of the three alternatives.)
A.5 Treatment of the data
The frequency of correct responses and the accompanying cer-
tainty ratings are computed for each symbol. If errors are substan-
tial, it is useful to carry out a more detailed analysis to make
clear which symbols are confused with each other. For purposes of
evaluating the SOS symbols, it is only necessary to look at the
confusion between SOS symbols and for each individual SOS symbol.
ANNEX B
(to Recommendation E.121)
During the Study Period 1981-1984, two experimental studies
were conducted in order to develop an appropriate set of symbols.
In either one study or both studies, the following Administrations
and manufacturers took part: AT&T, USA; Bell-Northern Research,
Canada; British Telecom, UK; Bundespost, FRG; Chile; France; ITT,
UK; KTAS, Denmark; The Netherlands; NTT, Japan; Sweden; Uruguay.
In the first study, in which 570 subjects from nine Adminis-
trations participated, a first selection was made from a set of
29 symbols for 12 common services. After a second experiment,
including 585 subjects from eight Administrations, a final selec-
tion was made.
In the latter study, it was shown that these symbols, if not
recognized immediately, can be learned in a few trials.
References
[1] IEC Publication 417 (1973) 5090-a.
[2] ZWICKER (E.) et al. : Critical bandwidth in loudness
summation, Journal of the Acoustical Society of America , Vol. 29,
pp. 548-557 (1957).
Recommendation E.122
MEASURES TO REDUCE CUSTOMER DIFFICULTIES
IN THE INTERNATIONAL TELEPHONE SERVICE
1 General
A common problem in customer dialling in the international
automatic telephone service is the erroneous dialling of the trunk
prefix of the country of destination. In the international service,
this trunk prefix must not be dialled. The following measures have
been tried and have proven very effective; they are recommended to
reduce this problem.
2 Recorded announcement
2.1 It is recommended that, at International Switching Centres
(ISCs) where the trunk prefix can be detected, the call should be
blocked and automatically routed to a recorded announcement which
would instruct the customer to dial the call again without dialling
the trunk prefix (see also Recommendation E.182, S A.2.8).
2.2 An example of such an announcement is: "Please do not dial
a zero after the country code when calling this country. Please
hang up and try your call again".
The exact source of the announcements would be any suitable
place, although it is preferable in traffic terms to use a source
as close to the call origin as possible.
2.3 The call is blocked and the announcement given from either the
outgoing ISC or the incoming ISC in the language of either the ori-
ginating or terminating country. It is not known whether the
language of the originating or of the terminating country is most
acceptable to the customers
2.4 When applying this method at an outgoing ISC, care must be
exercised in selecting the countries to which this measure is
applied, as the trunk prefix which is to be blocked might be a
valid trunk code for some countries. The employment of this measure
should be preceded by a review of the pertinent information includ-
ing national numbering plans and tests, as well as operator access
codes , and by an explanation to the other Administrations involved
of the plan to block calls having an erroneous trunk prefix.
3 Customer instructions
3.1 To avoid premature abandonment of attempted calls , custo-
mers should be advised to wait longer than usual for a call to be
established.
3.2 It is recommended that when Administrations prepare dial-
ling instructions for their customers they emphasize that the trunk
prefix should not be dialled in the international automatic tele-
phone service
This is necessary when the destination country conventionally
writes its telephone numbers such that the trunk prefix appears
with the trunk code (in parentheses). To compose a comprehensible
and accurate statement can prove difficult: suitable forms are
given below.
3.2.1 The first form is suitable for explanation. It could be
accompanied by numerical examples of complete international tele-
phone numbers:
"The trunk prefix zero that precedes the national trunk code
in several countries should be omitted after the country code in
international dialling. For example, to call Amsterdam (020) from
another country, you dial 20 after the country code for the Nether-
lands, which is 31. Some countries have a different trunk prefix
_________________________
In using the language of the originating country at an
incoming international switching centre, Administra-
tions should beware of using an inappropriate language
in cases where calls are routed through a transit coun-
try.
that should be omitted in international dialling. For example, in
Finland the trunk prefix is 9, while the trunk code for Helsinki
is 0; to call Helsinki (90) from another country, you dial 0 after
the country code for Finland, which is 358."
"Other countries do not normally include their trunk prefix
with the trunk code when writing telephone numbers: in such cases
you should not omit the first digits in international calling."
An example of the use of this statement is given in
Recommendation E.126, Annex A.
3.2.2 The second form may be more suitable in some contexts:
"In many countries, a special prefix (often a zero) is nor-
mally printed in telephone numbers with the trunk code, because it
must always be dialled for long-distance calls within that country.
This prefix must not be dialled when making international calls to
such countries. If your international call is not successful , you
should check to see if the first digit of the (apparent) trunk code
is a prefix that must not be dialled."
3.3 It is believed that widespread use of the notation given
in Recommendation E.123 for national and international telephone
numbers would lead to a reduction in the incidence of erroneous
dialling of the foreign national trunk prefix, and of other errors,
in international dialling. Administrations should encourage the
use of this notation.
Recommendation E.123
NOTATION FOR NATIONAL AND INTERNATIONAL
TELEPHONE NUMBERS
1 General
The statements below apply specifically to the printing of
national and international telephone numbers on letterheads, busi-
ness cards, bills, etc. Regard has been given to the printing of
existing telephone directories standard notation for printing tele-
phone numbers on letterheads, directories, etc., helps to reduce
subscriber difficulties and errors
1.1 The international number should be printed below the
_________________________
It is also desirable that the printing of other infor-
mation on letterheads, etc., such as telex and tele-
graph numbers and postal codes should not cause sub-
scriber confusion with the telephone number.
national number, with corresponding digits lined up one under the
other to facilitate understanding of the composition of the inter-
national number as shown in the examples in SS 1.3 and 1.4 below.
1.2 The words "National" and "International" in the appropri-
ate language should be placed to the left of the national and
international numbers, and these should be separated by a horizon-
tal line.
1.3 Either the symbol for telephone given in Recommendation
E.121 or the word "Telephone" in the appropriate language should be
placed to the left of (or above) the national and international
numbers (to avoid confusion with other letterhead numbers). The +
(plus) signifies the international prefix (see S 4.1).
Example: Telephone | nternational~~+22~607 ~123~4567
________________________________
(Additional examples are shown in S 6 below.)
1.4 Because the countries of World Numbering Zone 1 (North
America) have the country code 1, the same number as is used for
the trunk prefix, and because dialling between these countries is
the same as long-distance dialling within them, subscriber diffi-
culties are avoided by using an alternative notation that has been
found superior for use within these countries and equally good for
subscribers in other countries dialling to Zone 1. This is to sub-
stitute for "National" on the upper line the phrase "Within
N. Amer. zone".
Example: Telephone Within N. Amer. zone
(302) 123 4567 International +1 302
123 4567
1.5 If it is desirable to write only the international number,
it should be written in the form:
Telephone International +22 607 123 4567
1.6 To show an extension number of a PABX without direct
in-dialling, the nationally used word or abbreviation for "exten-
sion" should be written immediately after the telephone numbers and
on the same line as the word "telephone", followed by the extension
number itself.
Example 1: Telephone Within N. Amer. zone
(302) 123 4567 International +1 302
123 4567 ext. 876
Example 2: Telephone International +22 607 123 4567 ext. 876
In this way, the extension number is separated from the digits
to be dialled and, where it must be typed onto a letterhead, for
example, it need be typed only once.
1.7 It is often necessary to draw the attention of subscribers
to the need to omit the foreign national trunk prefix when dialling
an international call. This need occurs when the destination coun-
try conventionally writes its telephone numbers such that the trunk
prefix appears with the trunk code (in parentheses). To compose a
comprehensible and accurate statement can prove difficult: suitable
forms are given in Recommendation E.122, S 3.2.
1.8 Grouping the digits of a telephone number is advisable for
reasons of memorizing, oral presentation, and printing.
2 Classes of symbols
2.1 There are four classes of symbols in national or interna-
tional numbers. No symbol should be used in more than one class,
nor should any symbol within a class have more than one meaning.
2.2 These classes are:
- diallable symbols (in French: symboles servant a
la composition du numero );
- procedural symbols (in French: symboles
operatoires );
- information symbols (in French: symboles
d'information );
- spacing symbols (in French: symboles d'espacement
).
3 Diallable symbols
A diallable | symbol is a symbol which is to be dialled and
appears on a telephone set to designate either a finger hole of a
dial or a push button of a keyset other signs. Some desirable pro-
perties to be considered when selecting diallable symbols are
listed in Annex A.
4 Procedural symbols
A procedural | symbol is a symbol which tells the subscriber
how to dial. Such symbols should not appear in a finger hole or on
a push button because they are not to be dialled.
_________________________
Specific recommendations on the symbol for buttons 11
to 16 of a telephone keyset are contained in Recommen
dation E.161, S 3.
4.1 International prefix symbol
The international prefix symbol | should be + (plus) and
should precede the country code in the international number. It
serves to remind the subscriber to dial the international prefix
which differs from country to country and also serves to identify
the number following as the international telephone number.
4.2 Use of parentheses
The symbol ( ) (parentheses) should be used to indicate that
the digits within the ( ) are not always dialled.
The ( ) should enclose:
- the trunk prefix and trunk code in a national
number ,
- the trunk code when the trunk prefix is not in
universal use within a country.
This is done to remind the user not to dial the enclosed
digits for calls within the same numbering area.
The ( ) should not be used in an international number.
4.3 Multiple numbers reached through automatic search
For a subscriber with multiple numbers reached through
automatic search from the main number, only the main number should
be printed, without any symbol to denote the existence of the mul-
tiple numbers. This avoids encouraging subscribers to dial other
numbers in a group immediately after finding the main number busy,
a problem that is particularly important when only calls to the
main number are capable of triggering automatic search.
4.4 Multiple numbers without automatic search
For a subscriber with multiple numbers who does not have
automatic search, the symbol / (oblique stroke, solidus, or slant)
may be used to separate the alternative numbers.
Example A: (0607) 123 | 567 | | 23 | 272 | | 27 |
_________________________
It should be noted that certain Administrations, for
national purposes, use a hyphen between the trunk code
and subscriber number as a substitute for the sym-
bol ( ) parentheses in national numbers.
876
(0607) 123 | 567 | | 93 | 844 | | 64 | 692
+22 607 123 | 567 | | 93 | 844
To avoid dialling confusion in Example A, it is especially
important that there be a space on either side of the symbol /.
When it is desired to abbreviate the alternative numbers and
they are consecutive, only the last digit should be shown for the
alternative numbers.
Example B: (0607) 123 | 567/8/9
To avoid dialling confusion in Example B, it is especially
important that there be no space on either side of the symbol /.
The general use of / is to indicate a choice when dialling. It
may therefore also be used to indicate a choice of prefix codes as,
for example, the choice of dialling personal or station calls.
4.5 In-dialling
In the national and international number no symbol should be
used to show that a subscriber number is an in-dialling number of
a PBX. Where it is desired to indicate the existence of in-dialling
within a PBX and to indicate the in-dialling access code the fol-
lowing format is recommended:
(0607) 123 . | | |
(0607) 1 | 3 | | | |
The number of dots (periods) is equal to the number of digits
in the extension number of the PBX
On letterheads, subscribers could insert their own in-dialling
numbers in the dotted spaces. Presentation of the main listed
number should conform to S 1.3 above.
4.6 Symbol to indicate the existence of an additional dial
tone
_________________________
In many countries, a horizontal line element (-), e.g.
a hyphen in North America or a dash in some European
countries, is used in national telephone numbers as a
spacing character. Therefore, such an element is not
available to designate an additional dial tone. Some
Administrations, e.g. the Netherlands Administration,
on the other hand, uses the dash to indicate an addi-
tional dial tone and foresee a continuation of this use
for some time.
Some Administrations use one or more additional dial tone
responses as procedural elements, after the calling customer
obtains access to the public network. Where a symbol is needed to
indicate the existence of an additional dial tone, that symbol
should be the graphical representation of a full cycle of a sine
wave, or a close approximation to such a representation. It should
be placed at the point in the number where it is expected to occur,
and it should be preceded and followed by a space to avoid confu-
sion with a hyphen used as a spacing symbol (S 6.1). Its meaning is
to tell the user to wait for the additional dial tone
| Handwritten character:
Example ?02
| Typewriter character "tilde":
5 Information symbols
An information symbol is a symbol associated with the sub-
scriber number describing special features of the subscriber tele-
phone service, e.g., the symbol , where used, indicates that the
subscriber has an answering device attached to his telephone
[reference should be made to Recommendation E.117, SS 1a) and 1b)].
5.1 Such symbols are not to be dialled and therefore should
not appear in a finger hole or on a push button, nor can such sym-
bols be procedural in instructing the subscriber how to dial.
5.2 Information symbols should be associated with the word
"Telephone". To avoid confusion in dialling, they should not appear
either as prefixes or suffixes to the telephone number.
Example: Telephone (0607) 123 | 567 or
Telephone
(0607) 123 | 567
Some commonly used existing groupings are: Telephone
| nternational ~~+39~211 ~5432
____________________________ Telephone |
nternational ~~+41~71 ~78~901
_____________________________ Telephone |
nternational ~~+49~6 ~65~43~21
______________________________
See also the example below
6 Spacing symbols
Spacing symbols are symbols which are used solely to separate
parts of a telephone number from each other. They cannot be diall-
able, procedural or information symbols.
6.1 Grouping of digits in a telephone number should be accom-
plished by means of spaces unless an agreed upon explicit symbol
(e.g. hyphen) is necessary for procedural purposes. Only spaces
should be used in an international number.
6.2 In the international number, spacing shall occur between
the country code and the trunk code and between the trunk code and
the subscriber number.
6.3 The major separation among digits in a telephone number
(national or international) should occur between trunk code and
subscriber number. This separation should therefore always be wider
than any other separation within the number. This requirement is
automatically met in the notation recommended, as in the examples.
7 Facsimile number notation
The printed format for facsimile numbers should follow the
conventions set forth for voice telephone numbers except that fac-
simile numbers should be clearly labeled with the upper-case
letters FAX printed to the left of the numbers as illustrated here:
FAX | nternational ~~+49~6 ~65~43~21
______________________________ The
recommended appearance of the printed facsimile symbol (FAX) is
specified in Recommendation E.121.
ANNEX A
(to Recommendation E.123)
Desirable properties of diallable symbols
This annex lists some desirable properties to be considered by
the CCITT when this body standardizes new diallable symbols. There
are a large number of properties which are desirable for such sym-
bols, and those indicated below seem particularly relevant. How-
ever, their relative importance has not been evaluated, and it is
recognized that it may not always be possible to fulfil all these
conditions when selecting symbols
The properties of diallable symbols should be:
A.1 Distinct from other diallable symbols
As used here, "distinct" refers to dissimilarity from other
symbols compared with them visually, or aurally. The dissimilarity
should be evident in low probability of confusion with other
_________________________
Administrations using dots or hyphens as separators na-
tionally may require time to determine the consequences
of discontinuing their use.
symbols under degraded perceptual conditions.
A.1.1 The symbols should be visually distinct in their desig-
nated form as well as in typewritten, handwritten, or printed form,
including variations which might occur in each.
A.1.2 The symbols should be aurally distinct in naming them in
at least the official languages of the ITU.
A.2 Widely known name
The name of the symbol should be as widely known as possible
and be constant over as wide a range of population as possible.
A.3 Reproducible
The symbol should be easily reproducible in handwritten and
typewritten form.
A.4 CCITT-ISO compatible
The symbol should be one which is given as a member of the
CCITT Alphabet No. 5 and the ISO (International Organization for
Standardization) standard code for information interchange.
A.5 Made up of a single character
The symbol should not be composed of more than one individu-
ally valid symbol; nor should more than one key operation on a
typewriter, for example, be required to produce it.
A.6 Abstract
The symbol should not already have intrinsic meaning resulting
from other specialized usage.
A.7 Immediately recognizable as a diallable character
The symbol should not be one which is used for procedural or
information purposes.
Recommendation E.124
DISCOURAGEMENT OF FRIVOLOUS INTERNATIONAL CALLING
TO UNASSIGNED OR VACANT NUMBERS ANSWERED BY
RECORDED ANNOUNCEMENTS WITHOUT CHARGE
1 Preamble
It sometimes happens that there is a severe outbreak of inter-
national calling to telephone numbers that answer with recorded
announcements without charge. It seems that some subscribers make
such calls merely for free amusement. Frivolous calling can occur
unnoticed by an Administration unless it is deliberately looked
for, and serious degradation of quality of service can result.
This Recommendation concerns prevention and abatement of
frivolous international calling.
2 Monitoring
Administrations should be alert to changes in the rate of call
completion, or in the rate of calls completed without charge, or in
any other direct or indirect measures that could indicate the
growth of a significant amount of frivolous calling necessary to
confirm the existence of this problem.
3 Prevention
The following practices in one country may reduce the likeli-
hood of becoming the destination for frivolous calls from another
country:
- limiting the number of cycles of an annonounce-
ment;
- disconnecting when the limit is reached;
- offering no lengthy information without charge.
_________________________
The problem was first discovered in Japan after KDD no-
ticed a large number of calls lasting longer than one
minute without an answer signal being returned.
Where the signalling systems permit, the use of a back-
ward unallocated-number signal will allow an appropri-
ate tone or announcement to be returned to the caller
according to Recommendation E.181, S 2.
4 Abatement
4.1 When frivolous calls can be identified as originating from
the network of a particular Administration, the Administrations
concerned should arrange bilaterally to implement the most
appropriate prevention and abatement measures for the particular
case. This bilateral arrangement may include measures not recom-
mended for general application.
4.2 In general, vacant subscriber number announcements should
not be replaced by non-standard tones to reduce frivolous calling
because the use of unfamiliar tones might cause increased repeat
attempts by serious callers. Where particular numbers have been
identified as the targets of frivolous callers, replacing announce-
ments by tones for a limited period should not degrade the service
for serious callers. For this purpose only, a special information
tone is recommended.
4.3 When frivolous calling has been identified as causing
quality of service problems, it is desirable to detect the calls
and direct them to an appropriate announcement as close to the cal-
ling subscriber as practicable. The administrative and technical
difficulties of updating such arrangements for changes in many dif-
ferent numbering plans make the incoming international switching
centre the practical limit in most cases. By bilateral agreement,
however, frivolous calls might be blocked at the outgoing interna-
tional switching centre instead.
4.4 In accordance with Recommendation E.231, no charge should
be made for calls to subscribers whose service has been suspended,
cancelled or transferred. When calls to certain of these out-of-use
numbers have been identified as predominantly frivolous, the provi-
sions of Recommendation E.231 may be temporarily ignored for only
the particular numbers involved, until the problem is abated , and
subject to the agreement of the Administrations concerned. Calls to
these numbers would then have an answer signal returned and would
be charged unassigned numbers may be handled similarly. This meas-
ure would be immediately effective when frivolous calls originate
from payphones.
Recommendation E.125
INQUIRIES AMONG USERS
_________________________
Administrations should take care not to apply this
measure to non-frivolous telephone calls.
Some exchanges may require the addition of a function
to handle such calls in this manner.
OF THE INTERNATIONAL TELEPHONE SERVICE
One method of measuring telephone service quality is to con-
duct inquiries among users to ascertain their opinions of and
actual experience with, various aspects of the service they use.
These inquiries are have been developed and printed in previous
editions of the CCITT Book. These are:
a) questionnaire for national subscribers dialling
international calls;
b) questionnaire for visitors from other countries
dialling national or international calls.
The complete text of these questionnaires, as well as guide-
lines for their use, may be found in the CCITT Red Book ,
Volume II, Fascicle II.2, ITU, Geneva, 1985.
Recommendation E.126
HARMONIZATION OF THE GENERAL INFORMATION PAGES OF THE
TELEPHONE DIRECTORIES PUBLISHED BY ADMINISTRATIONS
1 General
1.1 It is recognized that users should normally have recourse
to the General Information pages of telephone directories when
looking for the information they need to obtain the required tele-
phone services and to apply the operating procedures correctly.
1.2 In addition, appropriate information in the General Infor-
mation pages of telephone directories may promote the development
of national and international telephone traffic and the utilization
of services by the national users.
1.3 Obviously foreign visitors too need to consult the General
Information pages of the telephone directories of each country they
visit and a similar presentation of the information in the various
countries will make their research easier.
1.4 Administrations should therefore see that the composition
of the General Information pages of telephone directories is har-
monized along the lines indicated below, with a view to making
available to all users of the telephone service a uniform source of
information which is satisfactory and easy to consult.
2 Guidelines
To obtain the required harmonization, Administrations should
set out the General Information pages of their telephone direc-
tories along the lines indicated below:
2.1 The General Information pages of telephone directories
published in various countries should contain similar indications
so as to facilitate consultation and the search for information by
foreign users.
2.2 The data listed in Annex A should always be included in
the General Information pages of the telephone directories pub-
lished by Administrations.
2.3 Each item of information should be presented, as far as
possible, in the order of priority indicated in Annex A.
2.4 The graphical presentation of information should be sug-
gestive and attractive to users (for example, through use of
letters and colours, and an appropriate arrangement in the opening
pages of the directory). The examples given in Annex A are illus-
trative only and no particular format is recommended.
2.5 For the sake of efficiency and to achieve the desired pur-
pose, especially for foreign visitors, care should be taken:
- to present the information in brief, concise and
clear texts, expressed in simple language;
- to use recognized and specific terms;
- to group all the information concerning a par-
ticular subject in a logical manner;
- to present the operating procedures in schematic
form, using symbols to explain the different sequences and not
lengthy descriptive texts, and using examples;
- to use the standardized symbols to identify
important numbers and services (symbols of national interest may be
used until such standardization is achieved) (see
Recommendation E.121);
- to use representative charts to facilitate the
application of operating procedures.
2.6 The last group of General Information pages should be
devoted specifically to foreign visitors; they should therefore be
printed in the most appropriate foreign languages and contain in a
shortened form most of the information and instructions necessary
for the correct exploitation of the telephone service (see
Recommendation E.127).
2.7 National trunk codes should be given either in the tele-
phone directory or in a separate publication.
2.8 The national and the international prefixes and a list of
country codes for all accessible countries should be given in the
General Information pages. A sample of foreign trunk codes may also
be listed in these pages; a more complete list may be provided in a
separate publication not necessarily published at the same time as
the telephone directories, and not necessarily distributed to all
subscribers.
2.9 The validity and usefulness of the information and
instructions given in the General Information pages and in the
separate "Guide" should be checked every time the telephone direc-
tories are reprinted.
2.10 Every Administration should be free to compose its tele-
phone directories in the way it considers most appropriate from the
national point of view, both with regard to form and content, and
taking due account of production costs. However, the type of infor-
mation to be included in the General Information pages, their
sequence and order of priority, should be in conformity with this
Recommendation, with a view to obtaining the harmonization
required.
ANNEX A
(to Recommendation E.126)
List of data to be included in the General Information pages
of telephone directories
Table A-1/E-126 gives the data and its priority for inclusion
in the General Information pages.
H.T. [1T1.126]
TABLE A-1/E.126
_____________________________________
_____________________________________
|
|
|
|
|
|
Tableau A-1/E.126 [1T1.126], p.16
H.T. [2T1.126]
TABLE A-1/E.126 (cont.)
_____________________________________
_____________________________________
|
|
|
|
|
|
Tableau A-1/E.126 [2T1.126], p.17
Priority 1
Index
Emergency services
Important and useful numbers
- Public utility services
- Auxiliary services
Instructions for using the telephone
- Operational procedure and tones
Procedures for obtaining different types of calls
- Automatic service
- Codes
- Operator service
- Charging for calls
- Time zones
Instructions for using the directory and explanation of symbols and
abbreviations
Public telephone
- Offices
- Booths
- Telephones made available for public use
Maps
Other information
- Recommended presentation of national and interna-
tional numbers
- Commercial and miscellaneous product service
- Subscription and invoicing
- List of directories and how to obtain them
- Administration: addresses and telephone numbers
Pages intended for foreign visitors
Figures Priorite 1 et 2, p.18
Figure Autres services, p.19
Priority 3
Instructions for using the telephone
Operating procedure and tones
- Make sure of the number of your correspondent or
of the service required by consulting the telephone directory or
your own address book.
- When you lift the receiver, the dialling tone you
will hear will be as follows:
Figure, p.
- After dialling the number, you will hear either
the ringing tone, which is as follows:
Figure, p.
or the busy tone, which is as follows:
Figure, p.
- Others: to be described as necessary.
Note - The tones are given as an example. For the graphical
representation of tones, see Recommendation E.121.
Figure Priority 4, p.
Codes
The "Guide to Codes" gives the trunk codes for all national
districts and the various country codes, possibly followed by fre-
quently used foreign trunk codes.
Operator service
- Local calls
- Trunk calls
- International calls
Figure, p.
Charging for calls | (The publication of this information is left
to the discretion of each country)
- Local calls (automatic and via the operator)
- Trunk calls (automatic and via the operator)
- Charging periods
- International calls (automatic and via the opera-
tor)
Time zones | (The publication of this information is left to the
discretion of each country)
Priority 5
Instructions for using the directory and
explanation of symbols and abbreviations
(The publication of this information is left
to the discretion of each country)
Priority 6
Public telephone
Offices
Information concerning:
- the services provided
- the charges applied
- other subjects, at the discretion of each country
Booths
Possible calls and charges
Telephones made available for public use
Permitted calls and charges
Priority 7
Maps
Maps may be used to indicate which areas are covered by the tele-
phone directory and which directories cover adjacent areas.
(The publication of this information is
left to the discretion of each country.)
Priority 8
Other information
Specific information
- Recommended presentation of national and interna-
tional numbers
In personal or business relations, every subscriber should
communicate to his correspondents:
- his national number, with the trunk prefix, for
receiving trunk calls, and
- his international number, for receiving interna-
tional calls, preferably in accordance with the following grouping
method:
Telephone | nternational~~+39~6 ~78~21~91
______________________________
corresponding for example, to subscriber number 78 21 91 in
Rome (6), Italy (39). The symbol "+" represents the international
prefix of the country of departure.
Warning - The trunk prefix zero that precedes the national trunk
code in several countries should be omitted after the country code
in international dialling. For example, to call Amsterdam (020)
from another country, you dial 20 after the country code for the
Netherlands, which is 31. Some countries have a different trunk
prefix that should be omitted in international dialling. For exam-
ple, in Finland the trunk prefix is 9, while the trunk code for
Helsinki is 0; to call Helsinki (90) from another country, you
dial 0 after the country code for Finland which is 358.
Other countries do not normally include their trunk prefix with the
trunk code when writing telephone numbers: in such cases you should
not omit the first digits in international calling.
General information | (left to the discretion of each country)
- Commercial and miscellaneous product service
Description: Information Tel. No.
- Subscription and invoicing
Information concerning:
a) categories of subscribers
b) contributions to installation, removal and
replacement costs
c) periodic rentals
d) conditions of subscription
e) data entered on periodic invoice
f ) methods of paying invoices
g) conditions for delayed payment
Information Tel. No.
- List of directories and how to obtain them
a) list of volumes covering various districts
b) conditions of sale of volumes
c) address of sales centre
- Administration: address and telephone numbers
Priority 9
Pages intended for foreign visitors
Description
One or more pages in one or more languages containing the
necessary information to enable foreign visitors to obtain correct
access to basic and vitally important services. The information
should cover the following points:
- general
- emergency services
- operating procedure
- tones
- national calls
- international calls
- reference for finding code numbers
- directory enquiries service
- charging periods
- telephone offices, telephone booths and tele-
phones made available for public use: operating details and special
tones.
Recommendation E.127
PAGES IN THE TELEPHONE DIRECTORY
INTENDED FOR FOREIGN VISITORS
1 General considerations
1.1 The number of people travelling abroad on business, for
tourism or for any other reason is steadily increasing; in general
such persons move about a great deal and thus have to contend with
the problems this involves.
1.2 To satisfy their needs, foreign visitors have to make fre-
quent use of the telephone; consequently Administrations strive to
provide them with the essential instructions on how to use the
telephone service for domestic and international calls.
1.3 In the interest of both users and Administrations, clear
and easily understandable official information should be available
wherever the telephone service may be used.
1.4 The telephone directory is the main official vehicle for
the circulation of correct, up-to-date information on the use of
the telephone.
1.5 To facilitate consultation of the General Information
pages in the telephone directory by foreign visitors, one needs to
include one or more pages in one or more languages to assist them
during the consultation process.
1.6 Administrations should therefore ensure, if there is a
need, that there are pages in the telephone directory specifically
intended for foreign visitors and that they are standardized on the
basis of the following basic provisions.
2 Basic provisions
To provide the greatest possible assistance in the use of the
telephone service, Administrations should apply the following basic
provisions:
2.1 Instructions enabling foreign visitors to use the most
common basic services and information concerning domestic and
international calls and the rates charged should appear in one or
more appropriate foreign languages and be assembled on one or more
pages inserted at the end of the General Information pages in tele-
phone directories.
2.2 The pages included specifically for foreign visitors
should contain a summary of the principal information and instruc-
tions requested for correct operation of the telephone service and
also a number of references to the more complete General Informa-
tion pages in the telephone directory, which foreign visitors will
have no difficulty in consulting if their contents are standardized
as is desirable (see Recommendation E.126).
2.3 The pages in the telephone directory intended for foreign
visitors should cover the main points listed below, developed on
the basis of criteria adopted for the directory itself.
2.3.1 Introduction
2.3.2 Regular information
- numbers of the emergency services
- prefixes (national and international)
- dialling codes of countries connected by the
international automatic service (with references to the General
Information pages or to a separate publication supplementing the
telephone directory)
- principal tones (with graphic representation):
"dialling tone", "ringing tone" and "engaged tone", with mention to
other tones, if necessary
- Telephone Directory Information and trunk codes
within the country and abroad.
2.3.3 Operating instructions for outgoing calls
- local
- trunk
- international (automatic or through the operator)
from:
a) ordinary telephones
b) payphones
c) public telephone offices.
Note - A reference to the operating instructions (if there
are any) in schematic form (see, for example, Recommendation E.126,
Annex A) in the General Information pages would be useful.
2.3.4 Payphones
- identification
- characteristics of the system (signals, credit,
coin return) and picture of currency and token used for payphones.
2.3.5 Public telephone offices
- identification
- service hours
- operator services.
2.3.6 References to the General Information pages relating
to:
- domestic and international telephone charges
- full rate and reduced rate periods
- time zones
- Administrations or Recognized Private Operating
Agencies: addresses and telephone numbers.
Recommendation E.128
LEAFLET TO BE DISTRIBUTED TO FOREIGN VISITORS
1 General
1.1 The ever increasing number of people travelling to foreign
countries generally need to use the telephone either to communicate
with their own country or with people in the country they are
visiting.
1.2 These people make many of their calls from payphones and
public telephone offices , where normally they can find appropriate
instructions for the use of the telephone service; others who make
their calls from hotels or private telephones may encounter diffi-
culties for lack of information.
1.3 To obtain more detailed information, foreign visitors may
consult telephone directories containing General Information pages
(see Recommendation E.126) and "Pages intended for foreign visi-
tors", prepared in one or more languages to facilitate consultation
(see Recommendation E.127).
1.4 In addition, a leaflet containing general information and
instructions for the use of the telephone is printed and distri-
buted to foreign visitors, either by the Administration of the
country of origin on departure or by the Administration of the
foreign country on arrival. Cooperation between Administrations is
necessary to ensure that information contained in leaflets is accu-
rate, and also to prevent possible duplication of leaflets.
1.5 Administrations should therefore ensure that the leaflets
to be distributed to foreign visitors have the widest possible
application and, in principle, are drafted in a uniform manner on
the basis of the following guidelines. However, each Administration
can prepare its own leaflet to be distributed either at home or in
any other country, with the content it considers most appropriate
from the national point of view.
2 Guidelines
The leaflets to be prepared for foreign visitors should have
the following features:
2.1 Structure
The leaflet should be of assistance to foreign visitors who
wish to use payphones connected to the trunk service and the inter-
national automatic service or who apply to public telephone
offices, besides being assisted by hotel operators.
2.2 Title
"Telephone Information".
2.3 Format
It should be of a convenient size (e.g. A4 format where this
standard is utilized), folded in three to form six small-size
pages.
The exact design of the cover need not be identical between
countries to permit designers some freedom of interpretation, but
should include the standard title and some indication of the coun-
try to which the leaflet applies, a prominant representation of the
telephone symbol (see Figure 1/E.121), an illustration of the pay-
phone widely used in the country, and some reference to the public
telephone service.
Note - A model of the leaflet in the required format and with
the particulars it should contain is given in Annex A.
2.4 Contents
- Introduction
- General information:
a) SOS - emergency numbers
b) Prefixes (national and international)
c) Destination codes of countries which can be
reached by fully automatic means
d) Main tones with graphical representation
e) Information about reduced rates , if any
f ) Telephone directory information and trunk codes
- Payphones:
a) How to find them
b) How to use them
c) System characteristics (signals, credit, return
of coins) and pictures of currency and token used for payphones
- Public telephone offices :
a) How to find them
b) Hours of service
c) Operator services
- Hotel and private telephones :
a) How to call
b) Surcharge
- Supplementary notes:
a) Reference to the "Pages intended for foreign
visitors" (that is, the last of the front pages of the telephone
directory)
b) Reference to the " Trunk code publication "
c) Time differences: time zones (front pages)
Note - An example of the text in general form is given in
Annex B.
2.5 Layout
It should be pleasing to the eye, in order to attract the
reader's attention, printed in black and white and in colour, with
clearly legible characters and also boldface type to display the
most significant information, with graphic representation of tones
and with pictograms and standardized symbols if these appear fre-
quently in the text. Sentences should be short, concise and simply
formed of words in current use.
2.6 Production and distribution
- Preferably, the version produced by each country
concerned in the appropriate language, should be available at the
places of arrival of foreign visitors, at public telephone offices,
travel agencies , etc.
- Optionally, the version produced by each country
may be made available at the places of departure of travellers, at
travel agencies, airports, railway station ticket offices , etc.
The choice of the method should be made on the basis of con-
sultation between the two countries concerned.
2.7 Validity
This should be clearly indicated with reference to the last
updating, and should be checked according to changes in contents
and distribution.
ANNEX A
(to Recommendation E.128)
Model of leaflet to be distributed to foreign visitors
H.T. [T1.128]
Page No.
lw(12p) | lw(84p) . lw(12p) | lw(84p) .
{ Germany 49 - 1 Great Britain 44 + 1 Greece 30 + 8 Japan 81 - 6
U.S.A. (New York) 1 other countries
}
Tableau 1/E.128 [T1.128] A L'ITALIENNE, p.25
H.T. [T2.128]
Page No.
_______________
Tableau 2/E.128 [T2.128] A L'ITALIENNE, p.26
ANNEX B
(to Recommendation E.128)
Sample text of leaflet to be distributed
to foreign visitors
TELEPHONE INFORMATION
Foreword
If you are abroad on a holiday or on a business trip and have
to get in touch with your family or with your friends or business
connections, you can do so in the most practical and economical way
by dialling your calls directly from a payphone. In this way you
would have no language problem.
If you want to benefit from special telephone facilities or if
you are short of the proper coins or of tokens, you can go to a
public telephone office where the personnel will advise you and
help you to call any country in the world.
The aims of this leaflet are to alleviate any anxiety you may
have about foreign languages, and to enable you to use the tele-
phone services without difficulty.
Information
SOS-for emergency calls dial: . | |
National prefix: . | |
International prefix: . | |
Country codes that can be directly dialled (see pages 5 and 6
of the leaflet).
Tones: dial tone
Tones: ringing tone
Tones: busy tone
(For graphical representation of tones see
Recommendation E.121.)
For directory inquiry service and telephone codes dial: . | |
Reduced rates.
Payphones
Payphones can be found in telephone street kiosks and, as a
rule, wherever a sign with a telephone symbol is exhibited.
Payphones work with coins (to be specified) or with telephone
tokens (value to be specified); the most modern payphone operates
with a "telephone card " and is located mostly in the airports and
main railway stations. The coins and the telephone token are pic-
tured here below:
Figure CCITT 78870, p.
Procedures for international calls
- Insert enough coins or tokens into the payphone
to make up a small credit.
- Lift the receiver and wait for the dial tone.
- Dial the international prefix followed by the
country code, then the trunk code (without trunk prefix) and
finally the subscriber telephone number.
Example
To call subscriber 12345 in Bristol (trunk prefix with
trunk code is 0272) in Great Britain (country code 44) you should
dial: + 44 272 12345.
Note 1 - It may be useful for you to jot down all the
digits in the right sequence before dialling.
Note 2 - The trunk prefix before the trunk code must not
be dialled in international dialling.
- Insert other coins or tokens to prolong duration
of the call as soon as you hear the special tone advising you that
your credit in the phone box has almost expired.
Once your call is finished:
- replace the handset;
- press the proper button on the phone box to
recover the unused coins and/or tokens.
Public telephone offices
The addresses and office hours of the public telephone offices
are shown at the top of the subscribers' list in the telephone
directory of each locality. Public telephone offices can generally
be identified by the street sign exhibited outside the building.
They are attended by trained personnel who can help you to obtain
your call when operator assistance is needed (personal, collect or
credit card calls, when such facilities are admitted).
Hotels and private telephones
When calling from a hotel you may be able to call direct after
dialling a code for access to the public network (this information
should be provided in your hotel room). In other cases you may have
to rely upon the services of the hotel operator. A surcharge will
normally be imposed by the hotel for any calls you make. It is
advisable to check what surcharge the hotel will impose before mak-
ing your call.
All services that are normally available from payphones can
also be used when calling from a private telephone. However, in
some parts of the country several telephones share a single line,
in which case the telephone line will not be available to all users
at all times.
Supplementary notes
More information can be found in the "Pages intended for
foreign visitors" which are the last of the front pages of the
telephone directory. A list of national trunk codes and another of
the main localities of foreign countries appears in the "Trunk Code
Publication".
To decide whether an international call can be made at a cer-
tain time, it may be convenient to consult the " Time zone chart of
the world " in order to check the corresponding time at the place
of destination. This information is given in the front pages of the
telephone directory.
Phone Home!
You will feel that you are there.
Recommendation E.130
CHOICE OF THE MOST USEFUL AND DESIRABLE | fR SUPPLEMENTARY
TELEPHONE SERVICES
1 General
The best choice of a supplementary service to be introduced
depends basically on the individual situation of a country. This
Recommendation only gives guidelines which should be carefully
appraised by the respective Administration.
It is suggested that a choice might be made from services
which are defined in the list of Supplementary Services (see Sup-
plement No. 1 at the end of this fascicle). Supplement No. 1 aims
to provide only outline information about the supplementary ser-
vices included, in order to give Administrations a broad idea of
the nature of these services. S 1 of the Supplement deals with
those services considered to have international implications and
seeks to specify these implications for each of the services con-
cerned. S 2 of the Supplement deals with those services not con-
sidered to have international implications. Appendix I to the Sup-
plement deals with those services not considered as supplementary.
The experience gained with these services by Administrations
which have already introduced the relevant service is given in the
form of remarks and market data within this list.
2 Items to be considered in choosing the most useful and
acceptable supplementary service
2.1 Marketability
2.1.1 Strength of customer's needs
- How intense is customer's need for the service?
- Does the service really solve the customer's
problem?
2.1.2 Expected market size
- How many users can be expected?
- Are substitute products or services available?
- Will there be a market restriction caused by com-
petition?
2.1.3 Customer's acceptance from the "human factors" point
of view
- Intelligibility of the context of the service.
- Procedures affecting easy understanding, easy
handling and easy memorizing.
2.1.4 Customer's price sensitivity
- Expected limit of charges to be applied for the
individual service or for the most common package of services, to
be used by the average subscriber. (A reference might be the
monthly rate of charges applied on normal telephone service.)
2.1.5 Cost/benefit ratio from the Administration's point of
view
2.2 Provisioning aspects
2.2.1 Technical requirements
- Will the present network be affected by traffic
overload caused by the new service?
2.2.2 Regulatory consequences
- Conflicts within present regulations.
- Problems concerning privacy protection.
2.2.3 Charging aspects
- Charging mode (e.g. per use or rental).
2.2.4 International implications
3 Basic realisation aspects
Three different technical solutions may be envisaged to make
supplementary services available to subscribers:
1) additional or modified software and/or hardware
of public networks (excluding terminals),
2) installation of special telephone terminals,
3) the combination of solutions 1 and 2.
As a guideline, the following aspects may be considered:
- Some services can only be realized by solution
No. 1 or 3. In those cases solution No. 3 will offer a better qual-
ity of service to subscribers because of the possibility of
improved handling. Such an improvement might be achieved by apply-
ing dedicated push-buttons, visual indication elements, user gui-
dance by pictograms and symbols, text displays, etc.
- If there is only a traditional electromechanical
system available, solution No. 2 may be the only economic way to
realize some supplementary services (e.g. abbreviated dialling,
number repetition).
- If the available system and the type of service
allows free choice between the three solutions, the following
aspects apply:
- solution No. 1 gives full flexibility in adapting
services to subscriber needs;
- solution No. 3 may improve the handling;
- solution No. 2 bears the same advantages to the
user as solution No. 3 and does not require special system
features.
Recommendation E.131
SUBSCRIBER CONTROL PROCEDURES FOR SUPPLEMENTARY |
TELEPHONE SERVICES
1 General
1.1 Many Administrations are planning to introduce supplemen-
tary telephone services which are likely to be viable only if con-
trolled by the user (a list of possible supplementary telephone
services is given in Supplement No. 1 at the end of this fascicle).
It is therefore necessary to consider means of providing users with
procedures by which such control can be achieved. The purpose of
this Recommendation is to prevent an undesirable proliferation, in
various countries, of subscriber control procedures for such ser-
vices. Descriptions are given below of three control procedures
schemes now in use or in various stages of evolution. Guidelines
are offered to Administrations planning to offer subscriber con-
trolled supplementary services. Reference is made to Annex A for a
glossary of terms used in this Recommendation.
1.2 It is recognized that not all aspects of all supplementary
services will affect the international telephone service , but a
degree of international coordination is considered necessary
because:
a) the same or similar supplementary services will
exist on national and international networks; it is desirable to
have similar control procedures for both applications;
b) a supplementary service which is only national
now may be international in the future; in that case changes in
control procedures might be impossible or expensive;
c) subscribers who travel or move will be less
inconvenienced if control procedures for supplementary services do
not change from one country to another;
d) compatibility between control procedures for
telephone services and simple parallel end-to-end data transmission
is highly desirable, because the same telephone instrument is used
in both cases;
e) standardized control procedures make possible
lower equipment and customer instruction costs.
1.3 Access to individual services requires that the supplemen-
tary service numbering plan have a sufficient capacity to meet all
reasonable future needs; control of the services requires the abil-
ity to define functional requirements to the system.
The introduction of push-button telephones providing signals
in addition to the normal decimal range (0-9) offers a means of
providing the necessary function signals. Since the 12-button
instrument is likely to be used by most subscribers, only two addi-
tional non-numerical signals will be available for control pur-
poses. Study therefore has been directed towards evolving schemes
for control procedures which are acceptable both from the human
factors and technical aspects and do not require more than two
non-numerical signals.
1.4 The same push-button telephone set that is used in dedi-
cated telephone networks may be used as a subscriber instrument in
service integrated networks. It is desirable that in this case the
control procedures for a given supplementary telephone service
still apply.
Where the normal 12-button telephone set is also used for ser-
vices other than telephony, e.g. for data, video-telephone, etc.,
the control procedures used for these services should be compatible
with the control procedures used for supplementary telephone ser-
vices.
2 Schemes for control procedures
Recognizing that:
- the CCITT has not as yet recommended a unique
scheme of subscriber control procedures for supplementary telephone
services;
- the CCITT is still studying such control pro-
cedures;
- further proliferation of schemes is undesirable
because this would result in subscriber confusion, less efficient
use of the telephone network and might make it more difficult to
work towards an optimum scheme;
it is recommended that:
- Administrations contemplating the introduction of
services which require new control procedures join actively with
the ongoing study;
- Administrations wishing to adopt a scheme of sub-
scriber control procedures should apply one of those detailed below
to the maximum extent feasible rather than establish a new scheme.
3 Description and analysis of code schemes for supplementary
telephone services
3.1 General
3.1.1 Three code schemes for supplementary telephone services,
currently in use or under study will be briefly described and
analyzed. They are:
1) AT&T code scheme (USA);
2) CEPT code scheme (Europe);
3) NTT code scheme (Japan).
3.1.2 It is intended that Recommendation E.131 should be
reviewed when experience of the three code schemes is available. It
may then be possible to determine if one of them, or perhaps a
fourth which incorporates the best features of all three, is to be
preferred.
3.1.3 These schemes are still evolving and are liable to
changes in details as study progresses or experience is gained. The
information presented is an outline only and presents the position
at a point in time when the Recommendation is published. Adminis-
trations considering the implementation of supplementary services
requiring control procedures should approach the appropriate
Administration or authority to seek detailed and up-to-date
information.
3.2 Description of the code schemes
3.2.1 The information sent by the subscriber to the exchange
for the control of a service is made up of a number of basic func-
tional elements, some or all of which may appear explicitly in a
particular message. These basic functional elements are (see the
glossary in Annex A):
1) mode or type of communication identification,
2) access to supplementary services,
3) service identification,
4) function identification,
5) supplementary information,
6) block separation,
7) message suffix.
3.2.2 The mode or type of communication identification element
is unlikely to be used for telephone services and allocation of
codes for this purpose within these schemes is tentative. This ele-
ment is therefore excluded from consideration for the present.
3.2.3 The main differences between the three code schemes are
in the methods used to encode the various functional elements and
the order in which they must be presented. In all code schemes a
separate code is used for the dialling of abbreviated numbers.
3.2.4 For each of the three code schemes, Table 1/E.131 gives
the format of the information sent by the subscriber to the
exchange:
i) without supplementary information,
ii) with one block of supplementary information,
iii) for the dialling of abbreviated numbers.
In the Table 1/E.131, the digits below each message identify
the functional elements as listed in S 3.2.1 above.
Table 1/E.131 (traite comme fig.), p.
The symbols used in Table 1/E.131 are as follows:
N = a digit;
SI = supplementary information;
SDT = second dial tone;
(. | | ) = not always used. For detailed
explanations, see S 3.2.5 below;
= "star" button of telephone set as
defined in Recommendation E.161;
= "square" button of telephone set as
defined in Recommendation E.161.
3.2.5 In the three code schemes the basic functional elements
are realized in the following way:
Access to supplementary services | (element 2)
AT&T: access prefix . (Customers are permitted to
dial the digits 11 in place of .)
CEPT: service code prefix or .
NTT: prefix digit 1 for services available from
both dial and push-button telephones, prefix for services avail-
able from push-button telephones only.
Service identification | element 3)
AT&T: a two-digit service code that is also used to
indicate the function: codes 72-79.
CEPT: two-digit (or exceptionally, three digit)
service codes beginning with 1-9 and 0 are reserved for CEPT allo-
cation in both PABX and public exchange fields.
NTT: two-digit service codes.
Function identification | element 4)
AT&T: the function is expressed in the service
code, different functions for the same service use consecutive
codes.
CEPT: service code prefix : activation and regis-
tration;
service code prefix : deactivation and erasure.
NTT: a numerical function code that is only
required for certain services. (If a function code is needed, the
subscriber is informed by means of a dial tone).
0 = deactivation,
1 = activation,
2 = registration.
Block separation | element 6)
AT&T: no block separation required.
CEPT: the standard CEPT control procedure will
assume the use of a block separator after the service code and
between blocks of supplementary information. As a national option,
the deletion of the block separator after the service code is
allowed; however, if in this case the subscriber dials a block
separator after the service code, the exchange should accept the
message.
NTT: the block separator may be used between the
function code and the first block of supplementary information, and
between successive blocks of supplementary information for
push-button telephones only.
Message suffix | element 7)
AT&T: the message suffix may be replaced by a
time-out.
CEPT: the message suffix is mandatory.
NTT: the message suffix is used for push-button
telephones only.
Abbreviated dialling
AT&T: abbreviated numbers: 2-9 and 20-49 available.
CEPT: N(N) abbreviated numbers: 0-9 and 00-99
available;
N(N) abbreviated numbers: 0-9 or 00-99 available.
NTT: abbreviated numbers: 00-99 available.
3.3 Features of each of the code schemes
The features of each of the code schemes compared with one or
both of the other two are given below.
3.3.1 AT&T code scheme
1) The symbol is used for access to supplementary
services.
2) Control procedures from rotary dial and
push-button telephones are compatible.
3) The messages sent by the subscriber to the
exchange are short.
4) Some two-digit codes have been reserved so as to
permit three-digit (or longer) service codes to be introduced in
the future without changes in the existing service codes.
5) The message suffix is not essential.
6) One, two and more digit abbreviated numbers are
possible without the need to use different initial digits.
3.3.2 CEPT code scheme
1) When only prefixes are used, the telephone
numbering plan is not influenced by the code scheme for supplemen-
tary services.
2) When only prefixes are used, exchange logic is
simplified.
3) When only prefixes are used, the use of similar
control procedures in PABXs and the public network is facilitated.
4) The abbreviated dialling numbering plan is
divorced from the service code numbering plan and does not impose
restrictions on it.
5) The service code remains the same irrespective
of the function required.
6) Each important function is defined by a unique
prefix.
7) Other prefixes are available for new service
functions.
8) A mandatory message suffix avoids the need for
time-out, fixed message length or complex programming.
9) When the message suffix method for abbreviated
dialling is used, one, two and more digit abbreviated numbers are
possible without the need to use different initial digits.
3.3.3 NTT code scheme
1) The use of a prefix simplifies exchange logic.
2) The use of a prefix facilitates the use of
similar control procedures in PABXs and the public network.
3) Other prefixes are available for future use.
4) A measure of compatibility between the control
procedures from rotary dial and push-button telephones is possible.
5) The abbreviated dialling numbering plan is
divorced from the service code numbering plan and does not impose
restrictions on it.
6) The service code remains the same irrespective
of the function required.
7) Each important function is defined by a unique
function code.
8) Ten function codes are available.
9) Allocating a function code after a service code
makes it possible to separate basic switching functions from sup-
plementary service processing functions. This facilitates the
application of new services to an existing old-type exchange.
10) The control procedures are similar to the con-
trol procedures in the NTT end-to-end communication services.
11) The function code can be deleted if not
required.
ANNEX A
(to Recommendation E.131)
Glossary of terms
This glossary gives the meanings currently allocated to vari-
ous terms to facilitate the study and evaluation of control pro-
cedures. They are subject to review as the code schemes evolve.
A.1 supplementary telephone service
F: service telephonique supplementaire
S: servicio telefonico suplementario
Any service provided by the telephone network in addition to
the fundamental telephone service.
A.2 control procedure
F: procedure de commande
S: procedimiento de control
A method in which information is exchanged in a predetermined
forward order and backward order between subscriber and exchange to
effect control of a service.
A.3 command
F: commande
S: instruccion (de control)
A single specific manipulation at the subscriber set causing
transmission of a signal which specifically indicates the manipula-
tion to the exchange. For certain control procedures either one
single command or a succession of commands are required.
A.4 character
F: caractere
S: caracter
A single specific symbol, number or letter used to designate
the diallable signal caused by a command.
A.5 message
F: message
S: mensaje
A defined entity of information from the subscriber to the
exchange pertaining to a call or a control operation for a service
sent in one sequence over the signalling medium. A message may con-
sist of one or more characters transmitted in one or more blocks.
A.6 code
F: code
S: codigo
One character or a sequence of characters forming a part, or
the whole, of a message with a specific meaning.
A.7 mode or type of communication identification
F: identification du type ou du mode de la communication
S: identificacion del tipo o del modo de la comunicacion
Information used to give an instruction to the switching
equipment to select the required network or mode of communication,
for example in the use of a multifunction terminal
(video-telephone, 48 kbit/s wideband switched-network service,
etc.).
A.8 access to supplementary services
F: acces aux services supplementaires
S: acceso a servicios suplementarios
Information used to instruct the switching equipment that the
associated information relates to a supplementary service.
A.9 service identification
F: identification de service
S: identificacion de servicio
Information designating a supplementary service.
A.10 function identification
F: identification de fonction
S: identificacion de funcion
Information indicating the type or types of process to be
applied to the service.
A.11 block separation
F: separation des blocs
S: separacion de bloques
Information indicating that the next character is the first
character of a block of supplementary information.
A.12 supplementary information
F: information supplementaire
S: informacion suplementaria
Any information, except the mode or type of communication
identification, access to supplementary services, service identifi-
cation, function identification, block separation and message suf-
fix, which is required to be sent by the subscriber to the exchange
for the performance of a control operation. The supplementary
information may consist of one or more blocks.
A.13 service code
F: code de service
S: codigo de servicio
A numerical code designating a supplementary service.
A.14 service code prefix
F: prefixe de code de service
S: prefijo de codigo de servicio
A non-numerical code preceding the service code and indicating
the type or types of process to be applied to the service.
A.15 function code
F: code de fonction
S: codigo de funcion
A code indicating the type or types of process to be applied
to the service.
A.16 block separator
F: separateur de blocs
S: separador de bloques
The character indicating that the next character is the first
of a block of supplementary information.
A.17 message suffix
F: suffixe de message
S: sufijo de mensaje
The character indicating the end of the message.
A.18 abbreviated number
F: numero abrege
S: numero abreviado
The numerical code sent by a caller using the Abbreviated
Dialling Service which identifies the telephone number of the party
to whom he wishes to be connected.
A.19 abbreviated dialling prefix
F: prefixe de numerotation abregee
S: prefijo de marcacion abreviada
The non-numerical code indicating that the information follow-
ing is an abbreviated number.
ANNEX B
(to Recommendation E.131)
During the Study Period 1977-80, an international laboratory
experiment comparing subscriber perform ance using two of the
recommended code schemes and a previous code scheme of AT&T, which
was defined in Volume II.2 of the Orange Book , was carried out
under the auspices of Working Party II/2 ( Human Factors ). The
experiment was conducted in five countries, Canada, Japan, Sweden,
the United Kingdom and the United States of America. In the experi-
ment, a sample of subscribers were brought into the laboratory and
asked to carry out a number of tasks involving the use of three
supplementary services. These tasks were carried out using a push-
button telephone connected to a simulated telephone exchange. A
different group of subscribers was tested using each of the code
schemes. Errors committed while carrying out the tasks and the time
required to complete them were recorded.
The results of this experiment revealed that there are no
large differences in subscriber performance using the three code
schemes. The experimental results did, however, reveal rather large
differences among tasks. Those tasks that required entry of supple-
mentary information blocks produced higher error rates. This sug-
gests that guidance announcements may be required to help sub-
scribers at each step in complex control procedures. However, it
should be pointed out that prior to carrying out the tasks only a
brief explanation of the required manipulations was given. It would
be desirable for experienced users to be able to override guidance
announcements by dialling. One particular task, ordering an alarm
call, produced quite high error rates in the entry of the time of
day. These errors resulted from the use of a 24 hours clock format
for entry of this information. This result suggests that a specific
positive recorded announcement with supplementary information may
be required to give the subscriber feedback on this point.
Recommendation E.132
STANDARDIZATION OF ELEMENTS OF CONTROL PROCEDURES
FOR SUPPLEMENTARY TELEPHONE SERVICES
1 General
1.1 CCITT Recommendation E.131 describes, in the form of code
schemes, three subscriber control procedures for supplementary
telephone services of control procedures, it recommends that
Administrations wishing to make supplementary telephone services
available to their subscribers should choose one of the three code
schemes.
1.2 Each of the three code schemes requires the subscriber to
send information to the telecommunication system to which he is
connected, in a set format and in response to feedback from the
system. Certain component parts of the information sent to the sys-
tem, such as the message suffix, block separators, tone signals and
the like, may be considered to be the necessary elements involved
in the successful operation of supplementary services
1.3 In order to minimize confusion to foreign visitors, and
maximize the benefits that accrue from using elements of known
meaning, it is desirable to standardize the usage of elements of
codes schemes whenever possible, in particular those elements com-
mon to all three code schemes.
2 Specific recommendation
2.1 Message suffix
It is recommended that the element known as " message suffix "
_________________________
As defined in Recommendation E.131, Annex A.
should be indicated by the symbol
The function of the element is to enable the subscriber to
signal to the system that he has input all the information he
intends to send at that time.
This Recommendation does not prohibit the use of the square
symbol for other purposes.
2.2 Supplementary information
For various services it is required that the subscriber sends
supplementary information to the telephone exchange for the perfor-
mance of a control operation. The interpretation of the contents of
the supplementary information blocks "year", "month", "day" and
"time" are specified below. This information can be used in various
services, such as alarm call service, do not disturb service,
absent subscriber service, agenda service.
The sequence of the information blocks within a control pro-
cedure is not yet specified.
2.2.1 Year information block
It is recommended to accept 2 or 4 digits as valid input for
the year information block.
If 2 digits are keyed in, this should be interpreted as a year
within the next 100 years.
2.2.2 Month information block
It is recommended to accept 1 through 12 and 01 through 12 as
valid input.
If no year information block is specified, the month is to be
interpreted as the month within the next 12 months.
2.2.3 Day information block
It is recommended to accept 1 through 28, 29, 30 or 31 and 01
through 28, 29, 30 or 31 as valid input.
If no month information block is specified, the day informa-
tion block is to be interpreted as the first day within the next
31 days.
_________________________
As defined in Recommendation E.161.
2.2.4 Time information block
Either the 24 hours or 12 hours clock format may be used. The
information block may contain 1, 2, 3 or 4 digits. To indicate a.m.
or p.m. in the 12 hours format an extra digit may be used. If 1
or 2 digits are keyed in, the information is interpreted as hours
with zero minutes.
One single zero, two zeros and a leading zero are accepted as
valid input; the number 24 and higher is not accepted.
If 3 or 4 digits are keyed in, the last two digits are inter-
preted as minutes. The last two digits may not be 60 or higher.
Leading zeros are accepted.
When neither month nor day is specified in another information
block, the time is interpreted as a time within the next 24 hours.
Recommendation E.133
OPERATING PROCEDURES FOR CARDPHONES
1 Preamble
Cardphones are payphones that accept cards as a means of pay-
ment. Many Administrations have deployed cardphones that accept a
variety of card types and technologies. (For further definition of
CCITT-recommended credit card types, see Recommendation E.118 on
the automated international telephone credit card system.) Card-
phones provide an attractive alternative to users through added
convenience and payment options. The service also provides benefits
to Administrations both economic and operational.
Prolifertation of cardphone terminals and technologies may
result in a multiplicity of customer operating procedures. The pur-
pose of this Recommendation is to offer guidelines that will:
1) facilitate customer convenience,
2) ensure ease of use through a common sequence,
3) standardize operating procedures to aid Adminis-
trations achieve lower equipment costs and customer instruction
costs,
4) increase revenues for Administrations.
2 Operating sequence
This section defines the sequence of actions in setting up a
call using a cardphone. Under each step there may be further points
of recommendation or preference, or additional comments.
2.1 Step 1: lift handset
Comment:
For a loud speaking telephone, step 1 is the action
equivalent to going off-hook.
2.2 Step 2: await signal to pay
Preferred:
It is preferred to have the dial tone precede payment, but
acceptable for it to follow Step 3.
Comment:
The signal may be the dial tone, some other signal or both,
e.g. display announcement.
2.3 Step 3: present means of payment
Recommended:
If a cardphone also allows payment by coins, initial pay-
ment should be in Step 3.
When a prepaid card is used the remaining value of the
card should be displayed before use.
When a card is successfully read and is verified as satis-
factory, the customer should be given confirmation.
When a card is determined to be invalid, the user should be
so informed, e.g. tone, display or announcement.
If further information, such as a personal identification
number (PIN), is required, it should follow after the card is read.
Comment:
A card may or may not be retained by the terminal during
some or all of a call set-up and connection.
The procedure for dealing with an apparently invalid card
is not within CCITT areas of responsibility.
2.4 Step 4: dial number
Recommended:
After verification, the required number can be dialled.
If the terminal has a display, it should not display the
PIN or other personal access digits.
Preferred:
Step 4 may precede Step 3, but the order given here is pre-
ferred.
2.5 Step 5: conversation or failure of call attempt
Recommended:
If the card is about to expire, the customer should be
given a warning (e.g. tone, display) and reasonable time (minimum
10 seconds) to either terminate the call or to insert an appropri-
ate means of payment.
2.6 Step 6: termination
Recommended:
Replacing the handset terminates the call.
Comment:
Where technically possible, when a credit card is used,
the call value or cost could be displayed.
If the cardphone has a "next call" feature, its operation
terminates a current call without the need to present a means of
payment again. The remaining value of a prepaid card should be
displayed.
2.7 Step 7: retrieval of card
Recommended:
If a card is retained by a terminal during a call, the ter-
minal should automatically eject the card when the handset is
replaced. In the case of special equipment, going on-hook is the
equivalent step.
Preferred:
If a card leaves the user's hand during the payment pro-
cedure, a method of reminding the user to remove the card should be
provided.
Comment:
A prepaid card should carry some indication of the remain-
ing value on the card itself.
Note - A tabular summary and an SDL description of the
procedure are contained in Annex A. The SDL diagram is provided as
reference for further study and is not a complete description of
the operating procedures. For example, differences in the status
found in the tabular summary, i.e. under the headings "Recom-
mended", "Preferred" and "Comment", are not stated in the SDL
diagram.
3 Glossary of terms
prepaid card
A card carrying a set amount of unit or monetary value that
can be used for telephone purposes. The card is decremented based
on use and can be either thrown away or re-valued, depending on the
technological attributes of the card.
ANNEX A
(to Recommendation E.133)
Human factors cardphone operating procedures
tabular summary
H.T. [1T1.133]
___________________________________________________________________________________________________________________________________________________________________________
Steps User action User options System reaction System options Status
___________________________________________________________________________________________________________________________________________________________________________
1 Lift handset {
With loud speaking telephone, going off hook is equivalent
} Comment
___________________________________________________________________________________________________________________________________________________________________________
2 Await signal to pay {
Dial tone should precede payment
} Preferred
This step may follow step 3 Comment
{
Signal may be dial tone, display or other
} Comment
___________________________________________________________________________________________________________________________________________________________________________
3 Present means of payment {
If used as coin phone, payment should be made at this step
} Recommended
{
Remaining value of prepaid card should be displayed to the customer
} Recommended
{
Customer should be given confirmation of successful card read
} Recommended
{
If PIN is required it should be input after the card is read
} Recommended
{
Card may or may not be retained during part or all of call
} Comment
{
Reaction to invalid card handling procedures is up to
Administrations
} Comment
___________________________________________________________________________________________________________________________________________________________________________
4 Dial number {
If PIN or personal access digits are required, they should not be
displayed
} Recommended
{
Step 4 may precede step 3 but the order given here is preferred (e.g.
restricted use cards)
} Preferred
___________________________________________________________________________________________________________________________________________________________________________
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Tableau A-1/E.133 [1T1.133], p.29
H.T. [2T1.133]
________________________________________________________________________________________________________________________________________________________________________
Steps User action User options System reaction System options Status
________________________________________________________________________________________________________________________________________________________________________
5 {
Conversation or failure of call attempt
}
{
Customer should be given an opportunity to prolong the call
} {
The system should give a warning and options in case of expiring means of payment
} Recommended
________________________________________________________________________________________________________________________________________________________________________
6 Termination {
Replaced handset terminates call
} Recommended
{
Customer may be given the option of a next call feature
} {
Next call feature allows for sequence calling without presenting means of payment again
} Comment
{
The value remaining on the prepaid card should be displayed
} Recommended
{
Customer could be shown value or cost of credit card call
} Comment
________________________________________________________________________________________________________________________________________________________________________
7 Retrieval of card {
If card is retained, terminal should automatically eject card at call
completion
} Recommended
{
Customer should be reminded if card not removed from terminal at call
completion
} Preferred
{
A prepaid card should carry some indication of the remaining value on the card itself
} Comment
________________________________________________________________________________________________________________________________________________________________________
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Tableau A-1/E.133 [2T1.133], p.
Figure A-1/E.133, p.